Countertop oven



FIG. 1 is a top, right and front perspective view as seen from the top, right and front sides of a countertop oven showing my new design in a first position;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a top, right and front perspective view thereof in a second position in order to show aspects of the design not otherwise apparent.

The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM The ornamental design for a countertop oven, as shown and described. 